This invention pertains to an electrical connector, including a terminator device and, in particular, it relates to a feed-thru insulation displacement connection (IDC) connector, including termination circuitry.
An application where reliable data transfers are important are in the field of data transmissions on a data bus transmission line for communication between a plurality of peripheral devices and a central processing unit in a small computer. For example, a small computer system interface (SCSI) bus provides for such a communication link. As is generally known in the art of designing bus transmission lines, a terminator, comprising of a resistor network, is typically connected to each of the physical ends of the bus in order to eliminate line reflection, created by the transmission of signals on the bus. Both of the terminators have a characteristic impedance equal to that of the bus.
Many peripherals, such as disk drives, are adapted to connect to the bus via flat ribbon cable. A bus terminator is generally attached to the flat ribbon cable, adjacent a peripheral device. FIG. 1 shows the common arrangement of the prior art, having an electrical connector having termination circuitry (a terminator) 10 attached to the flat cable 20. Adjacent the terminator 10, is an electrical connector 30 which is also attached to the flat ribbon cable 20. The electrical connector 30 provides for connection through a peripheral device such as a disk drive. Upon attachment of the electrical connector 30 to the peripheral device, it will then be attached to the bus via the flat ribbon cable 20 and terminated by the terminator 10, also attached to the ribbon cable 20. Both the terminator 10 and the electrical connector 30 are attached to the flat ribbon cable 20 via IDC connection. The process of attaching the terminator 10 and the electrical connector 30 is timely in that the ribbon cable 20 and the terminator 10 or electrical connector 30 must be carefully inserted in an Arbor press so that the IDC may be made between the rows of conductors of the ribbon cable 20 and the corresponding rows of the contacts of the terminator and electrical connector 30. Because the terminator 10 is separate from the electrical connector 30, the IDC process must be done twice.
In other prior art embodiments, the electrical connector 30 may be directly mated to a terminator which is in turn mated to a peripheral device. In such an arrangement, only a single IDC is necessary; however, misplacement of the terminator is possible. It is common to unplug the peripheral device from the bus. At such a time, the ribbon cable 20 having the electrical connector 30 attached thereto is separated from the peripheral device and the terminator is separated from both the cable 20 and the peripheral device. It is then not clear to most operators what to do with the loose terminator. Although it is preferable for the terminator to remain with the cable 20 in such an arrangement where the terminator is separate from the electrical connector 30, the two parts may easily be separated. Or the terminator may remain attached to the peripheral device and should attachment of the bus occur to another peripheral device, the termination may not be achieved at both ends of the bus.
Accordingly, there is desired an electrical connector terminator apparatus which avoids misplacement of a separate terminator and reduces the connection time of the electrical connectors to the flat cable.
It is, therefore, an object of the present invention to provide an electrical connector which may simultaneously terminate a bus and provide connection to a peripheral device.
It is another object of the present invention to provide an electrical connector and terminator package having a compact design which may be IDC connected to a flat ribbon cable.
It is a further object of the present invention to provide a terminator which includes a compact design which may be combined with an IDC connector.